Some San Francisco Safeway stores added gates barring shoppers from leaving unless they scan a receipt. It's an anti-theft measure that has spread across the UK.

• Safeway has installed receipt-scanning gates at some supermarkets in the San Francisco Bay Area.
• The gates are meant to deter theft at self-checkout.

Some California Safeway stores have installed security gates around self checkouts that won't open unless shoppers scan their receipts.

The gates are a theft-deterrent that's already widely used in the UK and could become more common in the US.

After customers at the Safeway supermarkets scan and pay for their groceries, they have to scan a code on their receipt to exit the store, the San Francisco Chronicle reported on Monday. The gates look like what you'd find at a transit station instead of a retail store.

"Recent changes were made at select Safeway stores in the Bay Area to maintain a safe and welcoming shopping experience for our customers and associates given the increasing amount of theft," a Safeway spokesperson said in a statement to Insider. "Those updates include operational changes to the front end of the stores to deter shoplifting."

"Like other local businesses, we are working on ways to curtail escalating theft so we can ensure the wellbeing of our employees and foster a welcoming environment for our customers," the spokesperson continued. Safeway did not say how many stores have the technology.

Safeway has been using the gates in at least one Bay Area store near the University of California, Berkeley since earlier this year, The Daily Californian reported in February. A Reddit post from this spring, meanwhile, showed the gates at another Safeway location in San Francisco.

Security gates at self checkouts is more common in the UK

Across the Atlantic in the UK, a handful of retailers already use the receipt-scanning gates at self-checkout areas. UK grocers Morrisons and Sainsbury's have added the gates at some of their stores. Clothing retailer Primark has also installed the gates at some locations, including one store in central Edinburgh visited last week by Insider.

Some people have compared the security gates to Costco's receipt-checking system. The warehouse chain requires all shoppers to present their receipts to employees who are stationed at store exits. These workers ensure that the receipts match the items in shoppers' carts.

But the mostly automated gates don't appear to be as stringent as Costco employees.

"I don't see what the barriers add, surely if you were going to steal from there you would buy a banana for 18 [pence] and put the steak in your pocket," a grocery shopper told the Sun in June.

Other British shoppers have said the gates don't make for a welcoming shopping environment.

"It's a supermarket, not a prison," one shopper wrote on Twitter in May. "Why do they choose to treat all of their customers as thieves?"

US retailers have also been adding security to their stores to discourage shoplifting. One Walgreens in San Francisco put chains and locks on the freezers where it keeps TV dinners and other frozen foods, Betty Yu, a reporter for CBS affiliate KPIX, tweeted on Monday.

Still, some retailers have said that their warnings about theft were overblown. In January, Walgreens' CFO said that the retailer had "cried too much" about theft after closing some Bay Area stores and adding security at others.

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